Hi @Victoria938,
Welcome to the HP Support Community
I'd like to help!
I understand you would like to know how to extend the output tray.
Follow the directions in the image to extend the tray.
Figure : Snap the output tray into place

Pull out the output tray extender, and then lift the paper stop.
Figure : Pull out the output tray extender

Refer to -https://support.hp.com/in-en/document/c03149951
Hope this helps! Keep me posted.
Please click “Accept as Solution” if you feel my post solved your issue, it will help others find the solution.
Click the “Yes" on the bottom right to say “Thanks” for helping